1. Field of the Invention
This invention relates generally to surgical access devices and more specifically to trocars and insufflation devices used in laparoscopic surgery.
2. Discussion of Related Art
Abdominal inflation is a critical component of Laparoscopic Surgery. The most common method to achieve inflation, more commonly referred to as insufflation, is to pass a sharp needle through the abdominal wall and into the inner abdominal region, and then inject a gas through the needle and into the region thereby creating an enlarged or ballooned cavity to accommodate a laparoscopic procedure. Unfortunately, insertion of the needle has been required without any visual aid to facilitate location of the sharp needlepoint. In order to reduce the probability of inadvertent penetration of delicate internal organs in this “blind” procedure, the sharp insufflation needle has been provided with a spring-loaded and retractable safety mechanism.
The safety mechanisms associated with most insufflation needles consist of a blunt or rounded member disposed within the lumen of the needle, and biased by a spring to an extended position beyond the needle tip. This spring must be responsive to the insertion pressure during placement of the needle but must be capable of immediately moving forward when that pressure is relieved. This is highly mechanical event and at best, offers a less than optimal arrangement.
In order to make the insertion of sharp needles into the abdominal region safer, a common practice has developed where the needle is inserted at an angle to the tissue plane. This of course requires that the needle traverse a greater distance through the abdominal tissue, so the maximum angle is always limited by the length of the needle.
Notwithstanding these attempts to reduce the probability and severity of an adverse consequence, many inadvertent injuries continue to result from the blind insertion of insufflation needles.